1.1 KiB
OpenSSL
OpenSSL is a software library for secure communication over computer networks.
Usage
Creating a key pair
As described by dreikanter
you can create and save a pretty secure private key to private.key with
openssl genrsa -aes256 -out private.key 8912.
After that run openssl rsa -in private.key -pubout -out public.key to save the
according public key to public.key.
Encrypting and decrypting files
Dreikanter
describes to encrypt larger files with symmetric encryption and encrypt the key
of that using asymmetric encryption.
If however the file is small enough to be encrypted with the public key
public.key directly run
openssl rsautl -encrypt -pubin -inkey public.key -in plaintext.txt -out encrypted.txt
where plaintext.txt is the message to encrypt and encrypted.txt is the
encrypted message.
You can decrypt the message using the private key private.key as follows
openssl rsautl -decrypt -inkey private.key -in encrypted.txt -out plaintext.txt.